The coronal sulcus is located at the junction of the body of the penis and the head of the penis, so named because its shape is a shallow ring-shaped groove in a coronal position. For people who are simply circumcised, the entire foreskin needs to be turned back to reveal the coronal sulcus of the glans. For people who are circumcised or have a narrow circumcision ring, the coronal sulcus is usually not visible. Circumcision can be performed to reveal the coronal sulcus. For people with long foreskin, the inner plate of the foreskin can secrete sebum, coupled with the accumulation of urine, the coronal groove can contain a large number of white foreskin scale, which is easy to breed bacteria and cause glansitis. Therefore, the coronal groove is a location that may harbor dirt and needs to be cleaned daily. In addition, the coronal groove is also easy to grow rash place, for example, long years of penile or circumcision of the crowd can grow strings of pearl rash, unclean sex after the crowd can grow warts and so on.